1. Field of the Invention
The present invention relates to an ink-jet recording method, an ink-jet recording apparatus, an ink tank to be removably mounted on such apparatus, and an ink-supplying means for supplying ink to the ink tank, which make possible to obtain a high-quality image on a recording medium. In addition, the present invention also relates to recording systems including a copying machine, a facsimile, and a printer, and also a word processor and a personal computer integral with a recording device, and a recorded material provided as a recording medium on which an image is recorded by the recording apparatus.
2. Related Art
Heretofore, ink-jet recording apparatuses have been used as output means on the commercial basis, for example they have been used as printers as output means of recording systems such as output devices of copying machines, facsimiles, electronic typewriters, and word processors, output terminals of work stations, and the like, and also such as handy- or portable-type printers equipped in information-processing systems such as personal computers and host computers, optical disk apparatuses, video apparatuses, and so on. In these cases, each of the ink-jet recording apparatuses is configured to meet a specific function, a usage pattern, and the like of the corresponding apparatus.
As a general ink-jet recording apparatus, it has been known that one comprises a recording device (recording head), an ink tank for storing ink to be supplied to the head, a sheet-feed device for feeding recording paper, and a control device to control these devices. The recording head that discharges ink droplets from a plurality of nozzles is serially moved or scanned in a direction (main-scanning direction) perpendicular to a direction of feed (sub-scanning direction). The ink-recording head performs a recording movement, in which the recording paper is intermittently fed a distance equal to the recorded width during non-recording intervals. In the case of a configuration of the ink-jet recording apparatus that uses an on-demand type recording head by which ink is ejected onto the recording paper according to recording signals, it has been widely used because of the advantages of low running cost and quietness. In the case of a configuration of the ink-jet recording apparatus that uses a full-line type recording head in which a plurality of nozzles for ejecting ink is arranged linearly in the sub-scanning direction, the recording head need only scan the recording paper once to perform recording of a width corresponding to the number of nozzles. This makes for increased speed of recording operation.
The supply supply of ink deteriorates in quality when the remaining quantity of ink in an ink storage member such as the ink tank described above is lower than a predetermined level. As a consequence, a poor printed output may be obtained and so high-quality image formation becomes difficult. If the tank becomes completely empty of ink, furthermore, an image cannot be formed on the paper while ink-ejecting means of the recording head is driven in spite of the absence of ink. In this case, therefore, the possibility exists of causing a failure of the ink-ejecting means. Especially in the case of using a heater for ejecting ink, as is described later, the possibility exists of destroying the whole structure of the recording head by the effect of abnormal heat-up. Conventionally, therefore, ink-jet recording apparatuses have a device for detecting the presence or absence of a liquid (hereinafter, also referred as a liquid-detecting device), as shown in FIG. 1.
The liquid-detecting device shown in FIG. 1 comprises a cylindrical rod 1001, a light source 1003 connected with the rod 1001, and a light-receiving unit (i.e., a photosensor). In this kind of the device configuration, the rod 1001 is in the type of having light transmission properties and also having a tip portion which is cut in a slanting direction. As shown in the figure, the rod 1001 is arranged in an ink tank 1002. The light source 1003 emits light toward a bottom of the ink tank 1002 through the tip portion of the rod 1001. In the case that the distance between the tip portion of the rod 1001 and the bottom of the ink tank 1002 is kept at a constant, the following conditions can be observed:
the condition that the tip portion of the rod 1001 is immersed in ink I (e.g., ink level is indicated by a solid line A higher than the tip portion); PA1 the condition that there is a space between the tip portion of the rod 1001 and ink level (e.g., ink level is indicated by a solid line A' lower than the tip portion); and PA1 the condition of empty out the ink tank 1002. PA1 a light-emitting unit for emitting light to a light transmitting portion having at least a part where a ridge portion or groove portion in the shape of V in cross section are formed on the ink tank; PA1 a detecting unit for detecting light which is reflected off the light transmitting portion; and PA1 a means for transmitting the results obtained by the detecting unit to a control unit of the ink-jet recording apparatus. PA1 an ink-storing portion for storing ink, provided as an ink-flow path for supplying ink to the recording means; PA1 a front end portion on which an ink-supplying opening for supplying the ink to the recording means; PA1 a rear end portion formed on the other side of the ink tank with respect to the front end portion; PA1 a side surface portion on which a window portion made of a light-transmitting material; and PA1 other side source portions for surrounding the ink-storing portion in conjunction with the side surface portion. PA1 a carriage on which an ink tank having a window portion of a light-transmitting material on at least one side surface thereof is fixed or removably mounted; PA1 a device for detecting the presence or absence of a liquid, which are arranged in a position facing to the window portion of the ink tank mounted on the carriage; and PA1 a control unit for determining the presence or absence of ink in accordance with the results obtained by the device for detecting the presence or absence of a liquid. PA1 an information processing unit for processing input information; PA1 an output unit for recording an output of the information processing unit on a recording medium; and PA1 a control unit for controlling an operating condition of the output unit, wherein PA1 the output unit having: PA1 a carriage on which an ink tank having a window portion of a light-transmitting material on at least one side surface thereof is fixed or removably mounted; PA1 a device for detecting the presence or absence of a liquid, which are arranged in a position facing to the window portion of the ink tank mounted on the carriage; and PA1 a control unit for determining the presence or absence of ink in accordance with the results obtained by the device for detecting the presence or absence of a liquid. PA1 the ink tank is for supplying an ink to a recording means, which is fixed on or removably mounted on a recording apparatus for recording an input image information on a recording medium by using the recording means that ejects ink, and comprises: PA1 an ink-storing portion for storing ink, provided as an ink-flow path for supplying ink to the recording means; PA1 a front end portion on which an ink-supplying opening for supplying the ink to the recording means; PA1 a rear end portion formed on the other side of the ink tank with respect to the front end portion; PA1 a side surface portion on which a window portion made of a light-transmitting material; and PA1 other side source portions for surrounding the ink-storing portion in conjunction with the side surface portion. PA1 the recording means is an ink-jet recording head that uses an electrothermal transducer for generating thermal energy required for allowing a phenomenon of film boiling to appear in ink in order to eject ink therefrom. PA1 the ink tank is for supplying an ink to a recording means, which is fixed on or removably mounted on a recording apparatus for recording an input image information on a recording medium by using the recording means that ejects ink, and comprises: PA1 an ink-storing portion for storing ink, provided as an ink-flow path for supplying ink to the recording means; PA1 a front end portion on which an ink-supplying opening for supplying the ink to the recording means; PA1 a rear end portion formed on the other side of the ink tank with respect to the front end portion; PA1 a side surface portion on which a window portion made of a light-transmitting material; and PA1 other side source portions for surrounding the ink-storing portion in conjunction with the side surface portion. PA1 a window portion formed on at least a part of a wall of the ink tank; PA1 a light-emitting unit for emitting light to the window portion; and PA1 a light-receptor unit for receiving light which is reflected off an inner wall surface of the window portion after emitting from the light-emitting unit, wherein PA1 a shape of the inner wall surface of the window portion is different from a shape of an inner wall surface of the ink tank around the window portion. PA1 the light-receptor unit is positioned on a path of light reflected from the interface between the ink and the ink tank after emitting from the light-emitting unit.
Under each of these conditions, reflected light having its own refractive index can be detected. Therefore, through the use of the differences in refractive indexes under the above conditions the presence or absence of ink can be determined by detecting whether the ink level is positioned between the tip portion of the rod 1001 and the bottom of the ink tank 1002. Thus the photosensor 1004 receives the reflected light passing through the tip portion of the rod 1001, and then the condition of the remaining quantity of the ink is determined by the control unit 1005 connected with the photosensor 1004. If the control unit 1005 makes a decision that the remaining quantity of the ink is lower than the predetermined quantity, the operator is instructed to change or fill the ink tank by means of an indicator on an operation panel (not shown) which is electrically connected to the control unit 1005.
However, in accordance with the conventional ink-detecting method described above, light emitted from the light source 1004 is reflected at an inner peripheral side wall of the rod 1001, so that it is difficult to keep a constant incidence angle of reflected light against a slant portion of the rod 1001 does not remain constant. It results in the problem that the difference between the strength of reflected light in the presence of ink and the strength of reflected light in the absence of ink cannot be broadly divided. In addition, it also results in the problem that the device configuration increases in complexity because of installing the rod 1001 in the ink tank (i.e., an ink-flow path of the ink tank). Furthermore, it is difficult to respond to consumer demands, such as for smaller and cheaper devices, to a sufficient degree because of enlarged volume and limited shape of the ink tank as a result of arranging the rod therein.